Engine Compartment Fire Extinquishing System

[edwardc]

Art,

To get back to your original question, I have a quite inexpensive manual system. It's called a "fireport".

It consists of a small (1 1/2 - 2") round fitting that has a window of soft, transparent plastic. The plastic is scored in an "X" almost all of the way through. The idea is that you can shove the nozzle of an ordinary handheld extinguisher through the port, allowing you to flood the engine compartment with CO2 without opening any covers.

[ndutton]

All these thoughts of mitigating normal engine box heat particularly in Tartans by incorporating additional ventilation in one way or another, please remember that in the event of a fire regardless of the firefighting method used you'll want (NEED) to disable the ventilation immediately to avoid extracting the smothering agent and turning the engine space into a blast furnace.

There, that should get me the record for the worst run-on sentence in forum history.

[ArtJ]

THanks for the inputs Neil and Ed

One additional point, the Tartan 34C and, I think, the Tartan 30
both have the Gas tank under the settee adjacent to the engine (gulp)
. That, combined with the batteries living right there too creates
a situation which needs immediate attention in the event of a fire.
I haven't spoken with Fireboy Tech support yet, but their models
CG2 and MA2 use HFC-227 Heptafluoropropane which I assume
is a newer replacement for Halon?

The original question was about the ambient temperature setting off
prematurely.

Any Fire would need to be dealt with instantly, but not at the
expense of going off prematurely automatically.

Thanks
Art

[romantic comedy]

Art, what do you do to cool the exhaust and stop it from getting too hot?

[ArtJ]

I cool the engine with two layers of exhaust wrap and also use a piece
of stove pipe wrapped around it near the 90 bend up to the standpipe.

The engine is fresh water cooled.

I just spoke with Tech support at Fireboy.
He said that the CG2 and MA2 extinquishers can only be automatic supplemented with a manual cable.
He said that they will go off at 170 degrees F and that cannot be
defeated or changed. He also said that the extinquisher is safe for
humans unlike Halon.

He said that typically customers state that their engine ambient temp
is around 130 degrees F. He suggests measuring the
ambient temp at the place I wish to install the extinquisher.
I am considering using the battery compartment
nearest the engine. ( I have previously created space for 4 large batteries,
but won't use 4 again, so have at least once empty space to use)

I have never measured the ambient temp in the battery compartment
and will do so upon spring startup. Do you have any idea about how
hot (Romantic Comedy) your ambient actually is?

There is also a provision for shutting down the blower built into
the extinquisher. He said there is no danger with the gasoline
engine running, unlike with a diesel and no harm will occur to the
engine. It will likely just sputter.

Regards
Art[/LIST]

[Don Moyer]

Tartan standpip temperature

Good question regarding what has been done to remediate the apparent critical temperature within the cabinetry around the standpipe. It seems counterintuitive to spend money for a fire warning system to alert one to a known hazard rather than to remediate the hazard. If you'll forgive a blatant infomercial, as I read more about the various strategies in this thread for dealing with the high temperatures around Tartan standpipes, it appears that the price of one of our stainless steel standpipes doesn't look all that bad. As our product description states, our standpipes have been designed with an improved water flow to cool off the exterior of the standpipe somewhat. It's difficult to quantify the improvement given the myriad variables involved, but customer feedback has been quite positive in reporting noticeably cooler temperature on the outside wall of the standpipe. Don

[romantic comedy]

Don, what about the hot section that leads to the standpipe? This is where the heat comes from. A brand new shiny MMI stand pipe would make no difference in a Tartan 34, as far as heat is concerned. It sure would look nice though.

The exterior of my standpipe does not get hot at all. I expect that is the same with others.

[ArtJ]

Don
I agree completely with Romantic Comedy.
The problem is the pipe leading into the standpipe, not the standpipe
itself. A double walled custom pipe, possibly water cooled would help.

There is also very little clearance in the plenium which houses the standpipe at the 90 degree turn.

Art

[romantic comedy]

Art, I dont know the temps. I do know that I would burn my hand, if I touched the wood next to the dry vertical pipe. Of course it depends on how long the engine was running.

I have one starting battery in the locker next to the engine. I have my house bank under the companionway/ladder. My huge heat exchanger is mounted on the bulkhead where the batteries were.

I covered the pipe with 3 layers of fiberglass insulation, but it still was too hot.

The way that the blower is designed is poor. There needs to be more air flow. Blowers are not designed for continuous operation, but many seem to stand up to being used that way. We need so serious air flow! An inline blower mounted above the standpipe might work best, but it would interfere with the nav station. (maybe)

My tubing idea was my way of trying to make it more mechanical, and avoid dependence on a fan. I need to rethink it, maybe. I will see.

Originally our boats had the forward air scoop feeding the bilge, and then the engine compartment. This was to improve air flow also. Many boats have changed or eliminated this. I dont have it any more either. Now I can trip on the windless instead of the cowl.

I have the cabinet around the pipe off, and have no proper bilge ventilation now.

[ArtJ]

I think a double walled exhaust pipe that has water flowing thru it would
help immensely.
This is actually a valid topic but different from my original post .



My original post of a fire extinquisher system was not in response to
excess heat, but rather to recover from a fire from a electical issue or
gasoline leak /fire.

[romantic comedy]

the double wall pipe would be ideal. It is just one of those things that are hard to make at home. Expensive too. I should just do it, and stop screwing around, and be done with it.

[ArtJ]

How is doubled walled made? Maybe someone makes it already, except
how would the angles be accomplished?

If it were kept dry (not my preference though) could simply sections of large sized steel pipe be placed over the existing system with
exhaust wrap in place? It would be better if it was a water proof jacket which could have exhaust water flowing thru it.

Don - Anything you could provide?

[Don Moyer]

Tartan exhaust issue

Sorry guys, I thought you were talking about the standpipe as well as the hot section. Don

[ArtJ]

Don

Can you help us with double walled exhaust?

[Don Moyer]

Double-walled pipe

We've never gotten into making custom double-walled pipe. Don